In storing foods, there have been used a polyvinyl chloride and a polyvinylidene chloride as a wrapping film for household or business use. However, since the generation of dioxin is likely to be caused by a large amount of chlorine atoms contained in the raw material resin of these films depending on the disposal and incineration methods, there has been developed a resin composition for a wrapping film which contains no chlorine atoms.
As a polyolefin-based wrapping film which contains no chlorine atoms, there has been conventionally known a single-layer or multilayer film comprising at least one layer of a film comprising a resin composition of a low density polyethylene and various resins and the like and a single-layer or multilayer film comprising at least one layer of a film comprising a resin composition of polypropylene and various resins and the like. In addition, a film obtained by further stretching these films is excellent in heat-shrinkable properties and is used as a film for stretch shrink packaging.
These packaging films are required to have a high shrinkage ratio as well as the transparency and gloss after shrinking in order to protect the contents and improve appearance of the contents.
In Japanese Patent Laid-Open Publication No. 2003-306587, there is disclosed a shrink film comprising a polyolefin resin composition comprising mainly a propylene-α-olefin copolymer having a low melting point (Patent Document 1).
Patent Document 1: Japanese Patent Laid-Open Publication No.
Also, a stretched polypropylene film is well known.